Planoobaph co



W. P. JENNEY.

WAR VESSEL. l APPLICATION FILED NOV. 3. |9l3 RENEWED JAN. 5. |917 1,313,945. Patented Aug. 26, 1919,

' 2 SHEETS-SHEET l.

40 e9 f a' 4 P TMB coLUMBIA PLANnGn/wll c l, 1 mw. vr

W. P. JENNEY.

WAR VESSEL. APPLICATION fiLED Nov. 3. |913. nsufwfu MN.5.1911.

1MB COLUMNA PLANOGRAPH co.. WASHINGruN o r .1 UNITED srnfrns PATENT onirica.

A wALrERrQJnNNEY, or WASHINGTON, DISTRICT or coLUMBIA.

Specification fLett-ers Patent. Patented Aug. 26, 1919.

Application 'filed November 3, 1913, Serial No. 798,989. Renewed January, 5, 1917. Serial No. 140,842.

To all whom it may concer/n.' Be it known that I, l/VALTER P. JENNEY, citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Im-` l provementsin'l/Var Vessels; and I do hereby f declare the following to lbe a full, clear, and i exact description' of the invention, such as y will enable others skilled, in thefart to which it appertains to make and use the same.

My invention relates to certain radical changes in the hull'of-vessels for general use, namely,` in the position of the reatest v inidship section or dead-flat, and in t e relative proportions and fineness of the forebody and afterbody, and also to the employment of under water fin-guards located over the propellers, with their planes conformable to the direction of the stream lines at that part of the stern. These said improvements enable me to greatly reduce the power required to drive the vessel at a given speed.

the water line a length greater than six times the maximum beam.`

Considering first the bare hull, without appendages; thc usual practice in naval architecture, at the present time, is to place the maximum beamor midship section or' dead-fiat at the mid-length of the vessel, equidistant from the forward and after perpendiculars, even though the length of the fore'body or the length of entrance, added to the length of the afterbody or length of run, may exceed six times the beam and in vessels designed for extremely high speed, the aggregate' length of these parts may even equal" a length of ten to twelve beams.

In my invention, on the contrary, the position ofthe maximum beam and midship section is 'not equidistant from the forward l and after perpendiculars; but is placed abaft they mid-length of the lau-ll,y and I- further em"` I' ploy a different coefiicient of iineness in the;

forebody from that employed in the afterbody, all as will be clear from what follows.

Referring to the accompanying drawings forming a part of this specification and in which like numerals designate like parts in allthe views :---A

Figure l is a diagrammatic perspective view of 'a vessel and its equal spaced transverse sections below the water line, showing the proportions between its volume and that of an inclosing right half-cylinder having a base equal to' the amidship section; which proportion is called ythe coefiicient of neness of the hull;

Fig. 2 is a water line plan view illustrating in full lines, a vessel built according to my invention, and indotted lines illustrating-a vessel built according to the present system; 1

Fig. 3 is 'a sectional View taken on the line 3.-3 of Fig. 2;

Fig. i is a sectional view taken on the line 4-40fFig.2; 1

Fig. 5 is a View of a mocliiied form of vessel. with a parallel middle body built on the old lines;

Fig. 6 is a view similar to Fig. 5 of a vessel having the same displacement, built in accordance with my invention; and with the parallel .middle body located albaft the midlength ofthe vessel;

Fig. 7 is a diagrammatic perspective view showing the direction of the stream lines in vessels when under way;

Fig. 8 is an enlarged detail view showing a fin set parallel to the direction of the stream lines over the screw propeller;

Fig. 9 is a plan view of the parts shown in `mal form, having alength of six or'- more beams, the positlon" Iof "the maximum beam most favorable for speed is influencedl and determined by what I call the optimum lcngtlpf run. `This said length of for abe'am-is a rstant, and the length of'runis a function' ot ithbeainfandlnot a function 0f the length of the vessel, as has been taught heretoforey The optimum length fined as the least or minimum length-ofthe aftei'body having a given coeicient ot'` lneness that Will-fair all Water passingfthe midf feiegoiiigciearership section, or Will produce disturbance 'insaid Water. n

A reference to the drawings Will make the If,"in Fg: 1', 'live' divide, the boat"8,'lat the ihidsliip section 1; then the ratio "or per-A forebody. Again considering the 'aftefbody of the boat S, containing theisections 9,' 10'y VV-aiid'l1, etc., 'the' ratio of thevolume of the afte'ibody to Tthe-volume of the' correspoiid' .ing portion of 'thehalf-cylinder` 7,' is44 thev Aicoeflicientofiineness of said afterbody.' 1' This ratio here termed the coetiicient of fine# -iiesshas also been known to those" skilled in New prior to my invention it has been eustoinaryto have'the-same coefficient of iine# f fiiessin the forebody, or'thatportion of the'- boat forward oit the midship section, as 1n the' azfteib'ody, orthat portion of the boat ahait the niidsliip section. Such old style' construction is illustrated in dotted lines iii# Fig.` 2, wherein 13 represents the inidship section, 14 the fore'body, and 15 the afterb'ody 'of-airfold style boat; ln this boat, it Will be` turtherseen that the afterbody 15 is as long' as the forebody 1i, it being, prior to my in-c -lventioinl believed that the length of the afa "teibody should depend upon the length of body isprovidedyvith a coefficient of finew ness which differs `fromv thecoeiiici'ent of;- u fneness of the aftei'body. 'IAccordingly,-con-i` f; 60-

having a1 given displacement, equal lengths offorebody and-afterbodyandthe same cos' efficient-oi' iinenes's ineachhalf, or through;-

them whole vessel, and not upon tlie length of .the beani'as Ifhave discovered.

-groater distance forward-ofthe mid'ship or greatest section 17, thandoesthe afterbody` 18. Notonly istl-ielforebody 16 of -a'greater lengtlifthaii the afterbody 418; but the fore,-

-sidei-'ing aivessel 'built priorlto my invention,

out .the hull, y as is illustrated -in' dotted lines the least eddy ha present'fstyleof vessel-arefurthercfemphaeeiitage'that' the volume of the forebod'y ofs v'flJLVgtllehull. Ithe 'boat' 8, liavingthe successivesections 4, 5 and 6, etc., bears to th'e volume-of the cor f responding forward portion of the half-cyli Hinder 7, is the-coeliicient of n'eness ofs'aid' ness forl the'entirevesehhvould yet have a' longer and sharper forebody 16 and a' shorter and relatively fuller afterbody 18, as is illusy trated by the full lines in Fig2. r :'lhedit ferences of shape between myvesseland the sized in the sectional views shown in Figs. 3

and 4f. The advantages-of this change of shape or design constltuting my invention, willpresently' appear, but an essentialfea- :ture-I of inynew Edesign is the optimu'nil length lof frllnfin the at'terbody 18, vhieh isv the 'least lengthi 'thatfwill efficiently vfair all Athe 'Water passingth niidship"section, or th'at'will create the r'least :disturbance `in4 'the' Water vessels, having 'transverse stern sections ofl'Vf-shape,"the optimiiivlength'o runzmay be l-define'd 'as "ht-Ween three and four times Athe inaximlini #.be'ani-,z' measured lat the @normal load` ivaterziline: i Ferl `Vessels having. lbroad hat@steris,` the:foptinn''1m length offrun is ltis'lslightly,supe'i-or in'smooth Water', as Vre- .ga-rds the'well'known residuary resistance; it -is-aptfto have'anfunnecessaryl area of wettedsnrfaeezand 1 is objectionable 'from a ''strLu-ituia-li and 'sea-'going :point of-vie'w. For 'this reason-EI pre-fer tomake the 'stern 'sections of the normal-V-shape usually einlployed in sea-`going high speed vessels- -I't the'lengtli-of-run is made less vthairthe opti'nlunigv the disturbance `of the Water in the wake isf ihereased, with corresponding in'creasein gresiduai'yresistance. On the other hand, a-lengtli'lof run greater than the voptimum causes: an increase in fricti'onal resistance; and: althoughlthis is offset by some decreaseiriresiduary-resistance, due to the added length of hull, .Ii-havefo-nd it to be -mofre advantageousto dispesesu'ch excess of length of body forwardof the midship section; .Where-litincreases tlie-length Vofthe or'ebody 16,@o`r entrance 'of the ship, aswill @be clear from-the foregoing. 1

f; lnthecas'e' o-'vessels with a\total length =equal tof-or less thansix beams, yit is obvious that ythe optimum length of run can seldom beemployed--and in e'onsequencethe length mit thehullf in such-vessels isf-commonly divided- 'in fthe' present type of,-vessels, "equally between `the length of.` runfoivafterbody 15,.:and-the ylength of entranceor fore- .wbody In the case, .-however, oflvessels *having a total length `on the Water line f --gieaten thanfsix times the inaximuinibeam;

that `is,1a length-more' than twice `the optifini Fig. 251th@:amasser-bant according to` a mum .length-Qtlam fforzitheigverribeami the soniewhatfless,'land'wvliile the bro'adl flat stern" excess: of length may be and is, adv-entail *geously added tothe length ot entrance, as'

abovestated, thereby making the length of 'entrance greater than the length of run, and

reduces the wave-'making resistance and at v'in consequence the position ofthe midship -'section is-moved a corresponding distancel aftfrom the mid-length of the hull.

Such `increase inthe length of entrance the same time, the run being given its opti* mum length handles all water passing the midship section in the most eflicient way.

" A little consideration will now show that the position of the midship section 17 rela-- tive to the after perpendicular, 1s fixed, be-

4ing distant the optimum length of run 18;

-times :the beam in extremely long vessels having a water line length of twelve beams.

For illustration, the length of run being the y optimum, (and for this example assumed with a constant length of three and one-half i times the maximum beam) the length-of en- 4trance 16 for a hull eight beams long willl equal four and one-half beams; for a hull of lten beams,'the length of entrance will be six yand one-half bea-ms, and for a hull having a length of ten and one-half beams the length of entrance will equal seven times the beam.

In'this last instance the length of entrance is equivalent to and therefore has all the advantages of the entrance of a vessel of the usual construction, fourteen beams in length, having the maximum midship section situated as is usual, equidistant from the ends of the hull.

It result-s from this shift in the midship section that the length of the vessel on the water line is divided into unequal vparts forward and abaft said section; the areas of the load water line forward and abaft, and the displacement are also divided unequally.

. Further, it thus lies in the power of the naval architect to employ primary variable a coefficients, which in an ordinary vessel are y forward of the midship `section larger or 4smaller,. as the ease may be, than the corresponding coelicientot'- that part abaftv the midship section. These eoeiiicients referred to are the coefficient-s of fineness; the water lline coeflicient, andthe ratios of the beam to f the lengths.respectively` of the forebody and the afterbody. y y, This ability to split up these coeicients .enables me to adjust the rela-tive displace .placed over the broadest beam, minsty easily borne. La

ments j ofy thefo'rbody "and 'the l afterb'ody also by employing'af'relatively smallerl co- Hcflicient of neness'fforftheaftterbody than iter the Yforebody, it? is ypracticableto employ Athe minimum length xof rum "It is Vthis employment of a low `co'eflicient offineness -for the afterbody. 1' that enables i the optimum length of run tofbereduced to the minimum;

whileat the 'same time,l the use of a higher coeiicient' of inenes's lfor the forebody is 4madepossibleby .the increased length of entrance the final result being, that the easy lines of the afterbody enables itto fair the water displacedby the relatively greater displacement of the forebody, withoutma` terial increase in eddy resistance.

-As the forebody is lengthened, the reduction 1n resistance due to increase 1n the length of entrance,.continuesto bean important factor luntil. the entrance has ai length of five to six beams, beyond Whichjthe relative gain in the reductionl Orl-resistance,

although notable, becomes ypregressively less with further additions to the length of entranceA .n i. f

'It :ollows thatfves'sels built-according to v my invention, designed for hghfspeeds, say

coeihcient of ineness oi" the forebody.

A specific example may be Yfound in a torpedo boat destroyer of the `usual dimensions now in use inour Navy, or having a length say` of 10.5 beamsfthe length of run being 3.5 beamsandfits coeliicient of ineness 0.57 to, 0.60; `In such-case the length of entrance will be' seven beams, and its coefficient of fneness maybe 0.70 to 0.78, thus considerably enlarging the displacement and making thecoetlicient'o neness of the entire' hull 0.66 ,to ;0.'7O-without1'induly increasing the resistance.

This invention also yenables the greatest midship section to be shiftedaft to the most advantageous position `for the installation of the' motive power. That is to say, compared with a vessel ofthe normal form having the same length, beam, etc., the greatest breadth of the IhullI placed farther aft', so that the boiler roemsjandf engine rooms arewidened, giving relatively a generous space for; the machinery. Furthermore. these heavy ,weights are where they -In a"ship` of the usual form, the center of gravity of the load water line and the center of gravity 'andfcent'er of buoyancy of the ship, completed, are situated at or near the midship section; that is, at the mid-length of the hull. In the new form described, the

center of gravity of the load water line and gravity relative to thecenter of buoyancy being finally fixed by the disposition of weights and bythe load of the ship.

Another effect of shifting aft the midship section is to greatly increase the relative breadth of the after part of the hull, with a consequent increase in the area of support of the lstern portion of the vessel. Owing to this, and alsoowing to the ship trimming about its center offbuo'y'ancy as'i-a center,

there is a less tendency in the new style of vessel for the stern to squat at high speeds.

In the foregoing disclosure of theposition i of the midship section,fit i's tofbe understood that these vessels, although ofa diiier'ent conguration fromv the old style, are yet of the 'standard form,.or as it is 'sometimestermed, the normal form, and do not otherwise than herein stated, radially depart from the usual nav'al construction. In cases where the plane of the midship section is not vertical, but is inclined either forward or aft, the 'rnidship section for the purpose of this invention may be treated as occupying a substantially vertical plane, its intersection with the normal load water line determining the position of the greatest beam, as hereinbefore stated.

Ih the case Of vessels having a parallel middle body, as illustrated in Fig. 6, the length of the parallel body 25, is considered as 'deducted from the total length of lthe hull; the lengtliof entrance being the length of all that portion 16 of the hull situated forward of the parallel middle body 25, and the length of runthelength of that part 18 of the hull abaft the parallel middle body 25.

The foregoing new principles of construction have been demonstrated by along series of tests carried out in the model basinl'at the Tashington 'Navy' Yard. When my new style of vessel iscompared with the latest destroyers built by the Government having substantially the same ratio of length to beam, and whose trials have been published, the results of these 'tests show conclusively that materially less power is required to drive my form of lvessel at the `speeds attained in said trials.

` Not only do the above tests demonstrate the great advance in naval architecture that is achieved by my invention, but these said' r tests also demonstrate the ,greatI advantage of employing lfins on the hull in the position and ofthe character now to be described.

rllhese improved fin-shaped guards 30, are placed over each propeller 31, so as .to intervene'between the propeller and the surface of the water. They are permanently attached to the stern'of the vessel and fixed in such position that the angle 'between the plane of the load water `line-and the plane of the fin, is .such thatthe plane of the fin is conformable in direction to the stream lines 32 at the maximum or other selected speed of the vessel. The depth of submer- 'sion of these fin guards, at normal draft will` vary with the draft of the vessel, but will be sufficient, while providing clearance for the screws, to prevent their comingout of water under ordinary conditions'of sea, 'due to the pitching of the vessel.' One of the objects of these guardsl is to cover and protect the screws frominjury; as for instance, by collision with docks, or with Vlocks of canals,

`or byvstriki'ng iioating timber, and in other waysguards, these novel fins have in service, other -But indep'endent of their use as functions Vthat make their employment of special advantage, in that they steady the ship, and at high speeds tend to restrain the bow from rising and the stern from squatting, thereby causing the vessel to trim more 'nearly'on yan even keel than it would without the fins. Th'ese fins, interposed between the propellers Iand the'surface, also prevent air from being sucked down to the propellers and thereby lessen cavitation. In these ways and in other ways, the effect of these fins is to reduce the motive power required to drive the vessel.

My ns or guards 30 should be carefully distinguished from those submerged guards, formed by flat arms or loops of metal eX- tending around or encircling the screws, and which have a different function fr'om mine.

My invention overcomes the well known disadvantages 'and defects in the prior underwater guards and differs from them by providing guards that lessen the resistance of the vessel vin moving through the Water, as well as affording efiic'ient protection to' the screws frein accidental injury. They are the resistance of the water to a minimum.

In other words my guards are horlzontal or gently inclined planes, 'or plane-like' warped surfaces, interposed between the propellers and the surface; afiixed to the hull and reaching outboard so'as lto cover all exposed parts of the shafts and propellers.

They may preferably be shaped like the' lns of a fish and are attached to the hull with the plane of each fin conformable to the local stream lines, so as to operate with the least praticable eddying` and the least frictional resistance.

A long series of tests carried out at the Washington Navy Yard show conclusively that these said guards when applied to my type of vessel, prevent thesinking of the stern and in this and in other ways lessen the resistance to the assage of the vessel through the water w ile performing the other functions stated.

I do not confine myself to any special form or shape of these plane-like guards, for they may be widely varied in shape;

may be constructed on streamline forms, and may have their upper or lower surfaces convex or concave, as maybe found to be most efficient.

These said guards are particularly adapted to coact with an optimum length of run, for they aid in fairing the water passing the stern and add an additional surface against which the water reacts to aid in propelling the vessel, and thereby compensate for the diminished surface of said run.

What I claim is 1. A vessel having different ooeflicients of ineness in its forebody and in its afterbody, and having its midship section located abaft the mid-length of the hull, substantially as described.

2. A vessel having a total length exceed` ing six beams, a length of `run in its after- Gopies of this patent may be obtained for five cents each, by addressing the body less than four beams, a different coeficient of fineness in its forebody and afterbody, and an entrance of greater length than said run, substantially as described.

3. A vessel having a length of run less than three and a half beams; a dierent coefiicient of neness in its forebody and afterbody, and an entrance greater than four beams; substantially as described.

f1. A vessel having ns inclined to the plane of the load Water line; different `coefficients of neness in its forebody and in its afterbody, and having its midship section located abaft the mid-length of the hull, substantially as described.

5. A vessel having fins inclined to the plane of the load water line; a length of run less than four beams, dierent coefficients of ineness in its forebody and in its after- WALTER P. JENNEY;

Witnesses: T: A. WrrHERsPooN,

JOHN H. SIGGERs.

Washington, D. C.

Commissioner of Patents, 

